The present development relates to valves and more particularly to valves of the type commonly referred to as bellows valves.
The development is particularly applicable to an inverted bellows valve and will be described with particular reference thereto. The development provides an improved bellows valve structure as compared with those structures disclosed particularly in the commonly assigned U.S. Pat. Nos. 3,278,156 and 3,787,023.
Characterized by a bellows component serving to seal off the interior of the valve from the atmosphere and at the same time, to accommodate movements of the valve stem during the operating cycle, bellows valves have found increasingly wide acceptance. In principle, the bellows valve concept presents notable advantages in so-called "closed system" applications involving the handling of corrosive and/or hazardous fluids at high temperatures and pressures. Most known prior art bellows valves have, however, failed for various reasons to meet or exceed the rising standards imposed by increasingly sophisticated systems.
The bellows valve structure and method of assembly disclosed in the aforementioned commonly assigned U.S. Pat. Nos. 3,295,191 and 3,278,156 have proved to be valuable advances in the state of the art, although it has been found desirable to improve the basic design for purposes of permitting valve use in higher pressure and temperature applications than has heretofore been possible. It has further been found desirable to improve the basic valve design in a manner which would facilitate use of a so-called soft seat material to allow for valve control by either conventional handle means or by remote actuator means and to also provide a valve design which would permit the internal valving components to be readily removed from the valve body for repair or maintenance purposes.
The subject new design is deemed to fully meet these needs and provide a new and improved bellows valve structure yielding improved operational results through a wider range of pressure and temperature applications.